Page 1 of 2

Bike repairs...

Posted: Wed May 02, 2007 3:24 pm
by bigmark100
The chain on my bike broke today :-( . I took it too a shop and they have said I need to replace the crankshaft, cassette and chain.
Apparently the crankshaft is worn. So a broken chains gonna cost me close to $500 - its a Shimano 105.
Do I trust the shop and go ahead with it? Or should I get a second opinion.

and any idea of how easy it is to replace these bits yourself?

Posted: Wed May 02, 2007 3:33 pm
by sogood
How long have you been riding that bike and for what kind of distance?

Running gears do wear down and require replacement over time, so what's said is a real possibility.

As for the front, it may be cheaper or not to just replace the chainrings.

In general, a cassette will last at least two sets of chains if the chain is changed within its spec life. Once over that, it'll wear out the cassette and the chainring. Sounded like your running gears have had a long life already.

Doing it yourself is not hard but you'll need some specific tools which probably will equate to the labour charge for the job.

Posted: Wed May 02, 2007 3:56 pm
by mikesbytes
Also, is it 9 speed 105 or 10 speed ?

I go thru a cassette every 9 - 12 months, chain every 6 months and front chain rings every 2 years.

_________________________________________________________________________________
Burn plenty of Glycogen
Frame Size Calculator.....Park Tools Repair Guides Frame Size Calculator.....Rolling Resistance.....Rolling Performance.....Sheldon Brown's Bicycle Technical Info
training log.....Body-Mass Index, Waist-to-Height Ratio, Basal Metaboic Rate
Bicycle FAQs.....Bicycle Safety.....Cadence in Cycling.....Types of Bicycles

Posted: Wed May 02, 2007 4:06 pm
by bigmark100
9 speed.
Ive had the bike for 3 years - but riding only regularly in the last 18 months. milage is about 2-3 thousand kms....

I am happy to have it replaced - if its from normal wear and tear, but fairly new to having a decent bike and having it serviced...etc.
just wanted to be sure Im not being taken for a ride......
I guess Im in shock - going in thinking I only need a new chain when it turns out be so much .

thanks for the responses...

Posted: Wed May 02, 2007 4:18 pm
by sogood
3000km is well within the life of a regular chain. But if you haven't done the proper cleaning and lubes, it's probably just reached it's service life. As such, changing the cassette and chainring should not be the norm unless there's some really extrodinary damages done to those components.

Posted: Wed May 02, 2007 4:32 pm
by Richardwestmelb
With that much use, which isn't much, I would doubt anything needs replacing, even the chain could be rejoined.

Get another shop to have a look.

Posted: Wed May 02, 2007 5:06 pm
by Halfanewb
Take a look at the teeth on the cassette and the chainrings especially the ones you use the most , are they shaped like sharks teeth with the side edges nearly meeting together in a point? if so they will need replacing, if they have a nice even set of flat tops then they wont need replacing.

You may be able to compare the teeth on the lesser used gears on the cassette to get some indication of wear on the most used ones.

Is there any play in your cranks? grab the pedals and try and move the crank vertically up and down, im no expert but the crankshaft is a harder metal than the bearings, so its the bearings that should be worn out if there is any play. And if there is play there is allways the chance that it might just need a minor adjusting or replacing the bearings.

$500 is a lot of cash - take a peek at these prices, check out this Cassette, this Chain and this 105 Chainset from Probikekit, most orders have a postal time to aussie of 7 days.

Chainsets can last upwards of 10,000k with proper maintenance, so on first impressions I would be very sceptical of this guy at the bike shop, but then im making that judgement based on the info your giving us :)

Posted: Wed May 02, 2007 5:58 pm
by uMP2k
Agree that while it is "within the realms of possibility" that you may need to replace the lot - it seems a bit of a stretch. It would be worthwile getting a second opinion and if necessary looking at some of the online stores for cheaper prices.

Posted: Wed May 02, 2007 6:29 pm
by pugsly
Just to hijack this thread slightly, what sort of life would you expect to get out of the 'wearable' components on a bike, the chain, cassette, bearings etc? I don't expect to wear anything out anytime soon, but in a way, it would be nice to be doing that much riding. :)

I guess it has a bit to do with the quality of the components, but is the difference that marked?

Posted: Wed May 02, 2007 6:49 pm
by MountGower
It's

Posted: Wed May 02, 2007 8:21 pm
by beauyboy
I have to tend to agree somethings does not sound right :? .
I would be goin past another shop and getting another quote and advice. What type of bike do you ride?
How do you ride?
How often do you oil your chain?
I just had a Look at my Discovery which has now been retired as I upgraded. It has covered a similar distance and while the Cassette and Chain rings are showing wear they are not to the point of replacement.

To me 500 is excessive for the short distance that you have covered, so brings me back to my first question, What do you ride?

Donald

Posted: Wed May 02, 2007 8:47 pm
by mikesbytes
pugsly wrote:Just to hijack this thread slightly, what sort of life would you expect to get out of the 'wearable' components on a bike, the chain, cassette, bearings etc? I don't expect to wear anything out anytime soon, but in a way, it would be nice to be doing that much riding. :)

I guess it has a bit to do with the quality of the components, but is the difference that marked?


Figures will vary considerbly depending on the rider, the conditions being ridden in, how vigours you are with cleaning it and the quality of the equipment.

For me, it seems that I get 3-6,000k out of a chain, 6-12,000k out of a cassette, 12,000k out of the big ring and 24,000k out of the small ring.

_________________________________________________________________________________
Burn plenty of Glycogen
Frame Size Calculator.....Park Tools Repair Guides Frame Size Calculator.....Rolling Resistance.....Rolling Performance.....Sheldon Brown's Bicycle Technical Info
training log.....Body-Mass Index, Waist-to-Height Ratio, Basal Metaboic Rate
Bicycle FAQs.....Bicycle Safety.....Cadence in Cycling.....Types of Bicycles

Posted: Wed May 02, 2007 8:52 pm
by mikesbytes
I would say that the bike shop is erring on the safe side. The approach I would take is to replace the chain and if its still slipping in a week, then replace the cassette. The problem with this approach, is that most riders would think that the bike shop had done a poor job - "I took it to the shop and it was worst than it was before", so unless the guys in the shop know you are an experienced rider who will understand why it is slipping, then they are going to simply replace the lot.

_________________________________________________________________________________
Burn plenty of Glycogen
Frame Size Calculator.....Park Tools Repair Guides Frame Size Calculator.....Rolling Resistance.....Rolling Performance.....Sheldon Brown's Bicycle Technical Info
training log.....Body-Mass Index, Waist-to-Height Ratio, Basal Metaboic Rate
Bicycle FAQs.....Bicycle Safety.....Cadence in Cycling.....Types of Bicycles

Posted: Wed May 02, 2007 10:19 pm
by Mr888
I was advised by my LBS that you should always change your cassette when you change chains and vice versa (...but nothing about the chainrings) The reason that was told to me was that deformations on the old part, if unchanged, will cause the new part to deteriorate prematurely. Hence you'll need to change one or the other or both again sooner.

He described it to me as changing your oil in your car without changing the oil filter and vice versa also.

...BUT at $500, that's a huge ask! A good chain should be around $40 and rear cassette $130 plus fitting. (You could get cheaper gear off eBay if you're handy). I'm not sure how much chainrings are (but don't think you'll need to change the cranks themselves), but estimate no more than $100. That's should be around only $270 for the parts. I don't think it's $230 worth in labour.

Can anyone second my opinion?

Posted: Wed May 02, 2007 10:26 pm
by sogood
Two chains for one cassette seemed to be the ratio I hear a lot on the net. However, I guess it also depends on one's criteria for chain replacement. Some go with that 1% elongation while others go with 0.5%. I guess the earlier you replace the chain, the more you protect the cassette and chainrings.

Posted: Thu May 03, 2007 9:48 am
by bigmark100
Well I told the shop to go ahead with the repair , before reading most of the responses here - doh. Should have waited it out.....
I've asked them to give me the old parts so I can have a proper look at whats actually worn. I'll post some pics up if anyone is interested.
The crank is going to cost $280, the cassette $99 and chain $49.
I guess an hour or two in labour is going to hit pretty close to $500 mark.

They did explain how the chain stretch, would mean that a new chain would not sit well on the old cassette.
Unfortunately when the chain broke - on a trip, I had nowhere to put it so just binned it. big mistake,

The crank was a suprise.

The bike I have is a Kona - Jake the Snake.
I ride daily - 15kms to work.
Quite a hilly ride - and do stand up and stress the bike out on the hills.
(Im 90kgs)

Posted: Thu May 03, 2007 9:49 am
by bigmark100
the bike shop also told me that if you want to prevent the cassette from being streched, then you should change your chain every 3 months.

Posted: Thu May 03, 2007 10:04 am
by europa
The shop owner doesn't drive a Porsche does he?

I've stayed out of this because I'm new to the fragility of modern parts, something that's only going to get worse as we keep adding more gears and being forced to use lighter and thinner chains.

Theoretically, if you change your cassette, you should fit a new chain because a stretched chain is only going wear your new cassette faster than a new one - but it's not going to kill your new cassette. The old theory was that a chain is cheap, but at $50 for one, they aren't cheap.

You do NOT have to replace your cassette when you change your chain, only when the cassette is worn and, as described above, that's checked by looking at the teeth on the cogs. I would regard two chains per cassette as cautious but considering the miles covered, not overly cautious.

What does the shop mean by 'the cassette getting stretched'? That's a new one to me.

A chain does not STRETCH - it flamin' can't. What happens is that the pins wear, allowing slop in the sideplate/pin bearing (often just a hole but not necessarily) which has the effect of allowing the chain to be longer when under tension. Yes, a worn chain will increase the rate of wear on your cassette.

How the hell does a crank wear out? Wasn't it done up tight? Did you feel it moving when you applied power? Was it creaking and making noises? Even then, just tensioning it properly should fix it unless you've let it go too long (in which case the movement will mess it up).

Look, the shop might be right in what it's saying. We can't say, but a lot isn't adding up with this story. It could be that you've just learned some valuable lessons about bike maintenance, it could also be that you've been taken for a ride. Mate, ask lots of questions and get them to explain everything - don't be aggressive or rude, because it could be you've missed some pointers in looking after your bike, but also have your bulldust detector set to 'sensitive' because you may find yourself changing shops.

I feel for your financial pain, but look at it this way, your bike, which you obviously enjoy, is having a birthday :D

Richard

Posted: Thu May 03, 2007 11:09 am
by mikesbytes
bigmark100 wrote:the bike shop also told me that if you want to prevent the cassette from being streched, then you should change your chain every 3 months.


Some people use 2 or more chains and swap them every time they clean the chain.

9 speed chains are something like $20 mail order. check out www.torpedo7.com.au

BTW, nine speed mtb chains are identical to nine speed road chains.

_________________________________________________________________________________
Burn plenty of Glycogen
Frame Size Calculator.....Park Tools Repair Guides Frame Size Calculator.....Rolling Resistance.....Rolling Performance.....Sheldon Brown's Bicycle Technical Info
training log.....Body-Mass Index, Waist-to-Height Ratio, Basal Metaboic Rate
Bicycle FAQs.....Bicycle Safety.....Cadence in Cycling.....Types of Bicycles

Posted: Thu May 03, 2007 11:38 am
by europa
mikesbytes wrote:BTW, nine speed mtb chains are identical to nine speed road chains.


Bet they don't cost the same :wink:

Richard

Posted: Thu May 03, 2007 11:49 am
by sogood
bigmark100 wrote:the bike shop also told me that if you want to prevent the cassette from being streched, then you should change your chain every 3 months.

With that message and your 15km/day commute, I would conclude that LBS is a con shop! Unless they put on some crappy quality chains and you ride in the rain everyday, there's no way you'll need to replace chains after 1500km.

Sorry to hear the major expenditure and I would suggest that you keep all the parts (as they may be reused or sold off on eBay). And yes, it would be good to post some closeup photos.

BTW, what's the name of that LBS? We should all know about it and avoid it.

Posted: Thu May 03, 2007 12:07 pm
by bigmark100
I wont name and shame until Im sure I was ripped off.
I've got a friend coming in to the shop with me who knows more about bikes mechanics and can check their story.
will keep you posted.

Posted: Thu May 03, 2007 12:38 pm
by europa
bigmark100 wrote:I wont name and shame until Im sure I was ripped off.
I've got a friend coming in to the shop with me who knows more about bikes mechanics and can check their story.
will keep you posted.


That's always the danger when you don't know what the bloke's talking about - misunderstanding and thinking you've been ripped when you haven't been. Mind you, better communication from the shop would help. Suck it and see.

Best of luck

Richard

Posted: Fri May 04, 2007 2:54 pm
by bigmark100
hi again,
ok - ive got my bike back, and still not really sure if Ive been ripped. total cost is $580. From what the mechanic showed me - there was wear with the threads within the crank, and I could concur that it needed replacing. The BB was thrown out so they were unable to show me the wear on this.

The replacement crank is a Shimano Crank 105 Compact 170mm.
The cost is $365. plus the BB - $75, The cassette is 9sp - 12/
12/23. $55 bucks.

I've tried finding the parts they have fitted on the internet - to verify the cost of them. but have not had much luck identifying them.
Is anyone able to tell me if Ive been over charged for these parts? Esp - the crankset. Which does seem very steep.
The code on the crankset says SG-X 105 60F.

thanks

Posted: Fri May 04, 2007 3:34 pm
by MountGower
BigMark